A liquid crystal optical device is known in which the distribution of the refractive index is changed according to the application of a voltage by utilizing the birefringence of liquid crystal molecules. Also, there is a stereoscopic image display device in which such a liquid crystal optical device is combined with an image display unit.
By changing the distribution of the refractive index of the liquid crystal optical device, the stereoscopic image display device switches between a state in which the image displayed by the image display unit is caused to be incident on the eyes of a viewer as displayed by the image display unit and a state in which the image displayed by the image display unit is caused to be incident on the eyes of the viewer as multiple parallax images. Thereby, a two-dimensional image display operation and a three-dimensional image display operation are performed. Also, there are examples in which the distribution of the refractive index is set to have a Fresnel lens-like configuration in such a liquid crystal optical device. In such a liquid crystal optical device, it is desirable to obtain high-quality optical characteristics by controlling the refractive index distribution to have the desired characteristics.